Performance and molecular parameters of broiler chickens fed diet with or without exogenous source of methionine and raised in organic or conventional production environment

According to the National Organic Program, synthetic amino acids are not permitted in organic production although low levels of synthetic methionine (Met) is permitted. The current national organic standard board (NOSB) recommended level (0.1% Met) pose issues and concerns for some organic producers citing lack of commercially available natural sources of methionine, and consideration pertaining to poultry health and welfare. Here, we examined the effects of complete D,L-Methionine (DLM) replacement by Brazil nut meal in organically raised broilers. It was concluded that the use of Brazil nut meal is a viable substitute for DLM in organically raised broilers, exhibiting no differences in growth and carcass yield compared to broilers fed a conventional diet and better feed conversion compared to broilers fed a NOSB organic diet. mRNA expression of genes in methionine metabolism suggests that an organic diet incorporating Brazil nut meal as a methionine source was comparable to a conventional diet containing DLM.